Purpose: To present long-term results of implantation of a black diaphragm aniridia intraocular lens (IOL) in eyes with congenital aniridia. Setting: Eye Hospital, Heinrich-Heine-University, Dusseldorf, Germany. Methods: Cataract surgery was performed in 19 eyes of 14 patients with congenital aniridia. The black diaphragm aniridia IOL was implanted in front of the capsular bag in the ciliary sulcus. Mean patient age was 30 years (range 10 to 59 years) and mean follow-up, 46 months (range 12 to 84 months). Before surgery, corneal epithelial disor ders; corneal pannus; cataract; hypoplasia of the macula, optic nerve, or both; and nystagmus were present in ail 19 eyes. Clinically detectable glaucoma was present in 5 eyes. Results: Despite the presence of amblyopia and nystagmus, visual acuity improved in 14 of the 19 eyes, The main postoperative problems were glaucoma deterioration (4 of 19 eyes) or development (4 of 19 eyes), cystoid macular edema (2 of 11 eyes), chronic endothelial cell loss (3 of 11 eyes), and progression of corneal epithelial disorders (4 of 19 eyes). Glaucoma was controlled by medical or surgical therapy in all patients. Intraocular lens explantation was performed in 2 eyes with glaucoma. Conclusion: Implantation ol the black diaphragm aniridia IOL improved visual acuity in the majority of patients with a variety of endogenous problems in addition to aniridia. J Cataract Refract Surg 2000, 26:375-381 (C) 2000 ASCRS and ESCRS.